Feasibility accuracy of three-dimensional echocardiography colour flow measurement on duct pulmonary dependent circulation

The assessment for patient with duct-dependent pulmonary circulation (DDPC) during the inter-stage intervals before first stage palliation commonly includes imaging of the heart with multiple imaging modalities. Recently, three-dimensional echocardiography (3DE) was found with the ability to delineate cardiac structure that is able to do 360o rotation. Therefore, this study aimed at identifying the accuracy of 3DE colour flow in measuring PDA size compared to computer tomography angiography (CTA). This study involves randomly selected 26 patients with DDPC undergoing CTA for palliation treatment in one year. The mean patient age is 1.6 ± 0.261 months with mean weight of 3.65 ± 0.82 kg. The full-volume 3DE colour flow acquisition was performed and analysed offline using Q-lab software. The PDA diameters at the origin as well as the insertion site were measured. The data obtained by 3DE colour flow data were compared to the CTA, which was taken as the gold standard. Results showed that the offline analysis of PDA size was feasible in all patients (100%) with the mean diameter of PDA at the origin on 3DE colour flow and CTA of 0.51 mm ± 0.14 and 0.52 mm ± 0.11, respectively (p = 0.92) . The PDA diameter at insertion site on 3DE colour flow and CTA was 0.29 mm ± 0.08 and 0.27 mm ± 0.97 respectively (p = 0.5). Meanwhile, the measurement of 3DE colour flow is comparable to CTA in measurement PDA size. However, the use of 3DE colour flow in infants with rapid heart rate is yet challenging to 3DE colour flow acquisitions

Evaluating the relationship of body mass index and waist circumference on the image quality of abdominal computed radiography

Body sizes of patients undergoing x-ray examination vary in body mass index (BMI) and waist circumference (WC). This study aimed to evaluate the relationship between BMI and WC on the image quality of abdominal computed radiography (CR). Anteroposterior supine abdomen projection was conducted on 69 patients from Hospital Raja Perempuan Bainun, Ipoh using a Siemens Multixtop general x-ray unit, and the images were processed with CR Carestream Direct view Max. Samples were categorised into normal BMI (n = 23), overweight (n = 23) and obese (n = 23). Image quality was measured quantitatively in signal-to-noise ratio (SNR) and qualitatively by visual grading analysis (VGA) based on the Commission of the European Communities (CEC) image criteria. Data were analysed by analysis of variance (ANOVA) and Pearson’s correlation for comparison and determining the relationship among BMI, WC and image quality. Results showed a significant difference (p < 0.01) in image quality of VGAmean (normal = 4.40 ± 0.15, overweight = 4.35 ± 0.13, obese = 4.03 ± 0.34) and SNRmean (normal = 60.79 ± 2.19, overweight = 59.66 ± 1.68, obese = 55.78 ± 4.31). A moderate to high negative correlation existed between SNR (r = −0.73), VGA (r = −0.7) with BMI (p < 0.01) and between SNR (r = −0.83), VGA (r = −0.79) with WC (p < 0.01). This study suggests that WC has a higher negative linear relationship than BMI and can be used as an effective image quality predictor for abdominal CR examination

Radiation dose obtained from abdominal computed radiography: comparison between supine and prone positions

The aims of this study were to compare the entrance surface dose (ESD) between anteroposterior (AP) supine with posteroanterior (PA) prone projection of computed radiography (CR) abdominal examination and to determine the relationship between body mass index (BMI) and ESD of a patient. AP supine and PA prone projections on the same patients for CR abdominal examination of intravenous urography (IVU) were acquired on 50 patients at Hospital Raja Permaisuri Bainun, Ipoh. All the radiographic examinations were carried out on a Siemens Multixtop general x-ray unit and the images were processed with CR Carestream Direct view Max. Entrance surface dose (ESD) in miligray (mGy) was measured using optical stimulated luminescence dosimeters (OSLD) calibrated by the Malaysian Nuclear Agency. Data were analyzed using dependent t-test comparing the AP and PA projections on the same subject and Pearson correlation was used to determine the relationship between BMI and percentage of reduction of ESD. Results showed a significant different (p < 0.01) between AP supine (mean ESD = 6.42 ± 7.13 mGy) and PA prone (mean ESD = 3.92 ± 3.56 mGy) projection at all BMI. The BMI has a positive correlation with percentage of reduction of ESD (r = 0. 61) and was statistically significant (p < 0.01). In conclusion, PA abdomen prone projection significantly reduces the radiation dose and there is a positive correlation between BMI and percentage of reduction of ESD. The use of PA prone projection for CR abdominal examination should be considered as the routine projection at all BMIs level. Awareness that as the BMI increases the ESD also increases at a moderate positive linear relationship

Brain activation display functional asymmetry in response to action, background and tonal frequency during a pitch memory processing: an fMRI study

In this study, the asymmetry of the main effects of action, background and tonal frequency during a pitch memory processing were investigated by means of brain activation. Eighteen participants (mean age 27.6 years) were presented with low and high frequency tones in quiet and in noise. They listen, discriminate and recognize the target tone against the final tone in a series of four distracting tones. The main effects were studied using the analysis of variance (ANOVA) with action (to wring (rubber bulb) vs. not to wring), background (in quiet vs. in noise) and frequency (low vs. high) as the factors (and levels respectively). The main effect of action is in the right pre-central gyrus (PCG), in conformation with its contralateral behavior. The main effect of background indicated the bilateral primary auditory cortices (PAC) and is right lateralized, attributable to white noise. The main effect of frequency is also observed in PAC but bilaterally equal and attributable to low frequency tones. Despite the argument that the temporo-spectral lateralization dichotomy is not especially rigid as revealed by the main effect of frequency, right lateralization of PAC for the respective main effect of background clearly demonstrates its functional asymmetry suggesting different perceptual functionality of the right and left PAC

Optimization of number of scans for a sparse temporal sampling (STS) functional magnetic resonance imaging (fMRI)

High sensitivity signal detection for a sparse temporal sampling (STS) functional magnetic resonance imaging (fMRI) is compensated by the increase in the number of scans (Ns) and consequently the scan time. A long scan time would result in fatigue and restlessness in participants, while a short scan time is undesirable for an STS-fMRI due to insufficient Ns for averaging. The purpose of this study was to determine the Ns practically sufficient for a sparse fMRI study. Eighteen participants were presented with white noise during a sparse fMRI scan. The height extent of activation was determined via t statistics and region of interest (ROI) based percentage of signal change (PSC). The t statistics and PSC for Heschl’s gyrus (HG) and superior temporal gyrus (STG) during which the participants listened to the white noise were calculated for different number of scans which were 6, 12, 18, 24, 30 and 36. The t statistics and PSC values calculated for the bilateral HG and STG qualitatively indicated a minimal change over Ns = 12 to 36. Both ROIs showed a consistent common right lateralization of activation for all Ns, indicating the right-hemispheric dominance of auditory cortex in processing white noise stimulus. It was proposed that for a sparse fMRI study, Ns may practically fall between 12 and 36

Diagnostic power of resting-state fMRI for detection of network connectivity in Alzheimer's disease and mild cognitive impairment: a systematic review

Resting-state fMRI (rs-fMRI) detects functional connectivity (FC) abnormalities that occur in the brains of patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI). FC of the default mode network (DMN) is commonly impaired in AD and MCI. We conducted a systematic review aimed at determining the diagnostic power of rs-fMRI to identify FC abnormalities in the DMN of patients with AD or MCI compared with healthy controls (HCs) using machine learning (ML) methods. Multimodal support vector machine (SVM) algorithm was the commonest form of ML method utilized. Multiple kernel approach can be utilized to aid in the classification by incorporating various discriminating features, such as FC graphs based on "nodes" and "edges" together with structural MRI-based regional cortical thickness and gray matter volume. Other multimodal features include neuropsychiatric testing scores, DTI features, and regional cerebral blood flow. Among AD patients, the posterior cingulate cortex (PCC)/Precuneus was noted to be a highly affected hub of the DMN that demonstrated overall reduced FC. Whereas reduced DMN FC between the PCC and anterior cingulate cortex (ACC) was observed in MCI patients. Evidence indicates that the nodes of the DMN can offer moderate to high diagnostic power to distinguish AD and MCI patients. Nevertheless, various concerns over the homogeneity of data based on patient selection, scanner effects, and the variable usage of classifiers and algorithms pose a challenge for ML-based image interpretation of rs-fMRI datasets to become a mainstream option for diagnosing AD and predicting the conversion of HC/MCI to AD

Resting-state fMRI: comparing default mode network connectivity between normal and low auditory working memory groups

The relationship between resting effective connectivity (EC) among default mode network (DMN) regions and auditory working memory (AWM) performance is still poorly understood. In this work, resting-state functional magnetic resonance imaging (rsfMRI) was used to determine the optimum connectivity model between posterior cingulate cortex (PCC) and medial prefrontal cortex (mPFC) in 40 healthy male volunteers. in low and normal working memory groups of subjects. Correlation between EC with AWM performance and AWM-capacity was also studied. The participants were divided into two groups which are normal and low AWM-capacity groups based on Malay Version Auditory Verbal Learning Test. The AWM performance was assessed using a word-based backward recall task. Both assessments were conducted outside the MRI scanner. The participants were scanned using a 3-T MRI system and the data were analyzed using statistical parametric mapping (SPM12) and spectral Dynamic Causal Modelling (spDCM). Results revealed that PCC and mPFC were significantly interconnected in both groups. Group analyses showed that the connection between PCC and mPFC exhibits an anti-correlated network. The results also indicated that the AWM performance and AWM-capacity were not associated with EC. These findings suggest that EC at rest between the two regions may not significantly influence cognitive abilities important for this AWM task

Validation of emotional stimuli flashcards for conducting ‘response to reward’ fMRI study among Malaysian undergraduates

Problematic Instagram Use (PIGU) is a specific Internet addiction disorder observed among the youth of today. Functional magnetic resonance imaging (fMRI) can objectively assess regional brain activation in response to addictionspecific rewards, e.g. viewing picture flashcards. Pictures that were uploaded onto Instagram by users with PIGU issue have often been associated with risky behaviors in their efforts to gain more ‘Likes’. Thus, it was hypothesized that individuals with PIGU issue are more drawn to negative emotional cues. To date, no literature on addiction-specific cues found on the local database. The objective of this study was to conduct an out-of-scanner validation study to create a database of pictures with negative emotional cues that evoke responses of arousal among individuals with PIGU issue. Forty-four Malaysian undergraduates (20 undergraduates in the PIGU group, 24 undergraduates in the control group) were randomly recruited as the subjects in the present study. They were grouped into PIGU or control groups based on the evaluation using the Smartphone-Addiction-Scale-Malay version (SAS-M) and modified Instagram Addiction Test (IGAT) and whether they fulfilled the definition of addiction according to Lin et al. (2016). They were administered with 200 content-specific pictures that were multidimensional, i.e. arousal (excitation or relaxation effects), approachavoidance (motivational direction) and emotional valence (positive or negative feelings) to describe their perceptions on the psychological properties of the pictures using a 9-point Likert scale. The results showed that the subjects with PIGU issue, who viewed the negative emotional cues, demonstrated significant positive correlations between arousal and valence (z = 4.834, p < .001, effect size = 0.69) and arousal and avoidance-approach (z = 4.625, p < .001, effect size = 0.66) as compared to the controls and were more frequently aroused by negative emotional type of stimuli. As a conclusion, a database of validated, addiction-specific pictures can be developed to potentiate any future cue-induced response to reward fMRI studies for assessing PIGU

The neurobiology of smartphone addiction in emerging adults evaluated using brain morphometry and resting-state functional MRI

The characteristics of smartphone addiction (SPA) can be evaluated by neuroimaging studies. Information on the brain structural alterations, and effects on psychosocial wellbeing, however, have not been concurrently evaluated. The aim of this study was to identify abnormalities in gray matter volume using voxel-based morphometry (VBM) and neuronal functional alterations using resting-state functional MRI (rs-fMRI) in emerging adults with SPA. We correlated the neuroimaging parameters with indices for psychosocial wellbeing such as depression, anxiety, stress, and impulsivity. Forty participants (20 SPA and 20 age-matched healthy controls) were assessed using VBM and rs-fMRI. The smartphone addiction scale –Malay version (SAS-M) questionnaire scores were used to categorize the SPA and healthy control groups. DASS-21 and BIS-11 questionnaires were used to assess for psychosocial wellbeing and impulsivity, respectively. VBM identified the SPA group to have reduced gray matter volume in the insula and precentral gyrus; and increased grey matter volume in the precuneus relative to controls. A moderate correlation was observed between the precuneus volume and the SAS-M scores. Individuals with SPA showed significant rs-fMRI activations in the precuneus, and posterior cingulate cortex (FWE uncorrected, p<0.001). The severity of SPA was correlated with depression. Anxiety score was moderately correlated with reduced GMV at the precentral gyrus. Collectively, these results can be used to postulate that the structural and neuronal functional changes in the insula are linked to the neurobiology of SPA that shares similarities with other behavioural addictions

The acceptance level of picture archiving and communication system amongst radiographers

Picture archiving and communication system know as (PACS) is a rapidly growing technology in the healthcare industry in Malaysia and provides a positive development for patient services and one of the factors that influence the success of this system is the level of user acceptance. However, the acceptance level of the radiographers in using PACS and also the factors influencing its usage are unknown. Thus, this study seeks to determine the factors that influence the radiographers on the acceptance of PACS in their daily tasks. A study was conducted in three hospitals to determine the level of acceptance of radiographers in the implementation of PACS and factors influenced it. A questionnaire applying the theory of 'Technology Acceptance Model' which uses components of perceived of usefulness (PU) and perceived ease of use (PEU) to determine the acceptance level of radiographers to PACS was used to collect data. Quantitative approach is adopted with questionnaire has been distributed to 76 radiographers at Pusat Perubatan Universiti Kebangsaan Malaysia, Pusat Perubatan Universiti Malaya and Hospital Serdang. Result analysis of stepwise multiple regression found that PEU was found an important influencing factor in determining the acceptance level of radiographers (R2 = 0.077) where this construct has resulted in radiographers do not feel overburdened in completing their duties. This study reported that radiographers are more interested in completing their job on ease of use while usefulness of the PACS system was not a main influence. Therefore, it is important for organizations which want to implement PACS to create an overview about PACS to the radiographers. The training should be given before the execution of system to enable acknowledgement of the advantages offered by PACS